Dental-engine handpiece



w. n. PORTER. DENTAL ENGINE HANDFIECE.

AAPPLICATION FILED SEPT-23, 1920.

Patentedept. 27, 19.21.

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PATENT; OFFICE.

`WILL R. PORTER, 0F PRINC BAY, NEW YORK, AssIGNoR To Tin s." s; wnrrn DENTAL MANUFACTURING COMPANY, A CORPORATION or PENNSYLVANIA.

ENTAL-ENGINE DPIECE.

Application ined september 23, 1920. seriaiNo. 412,333."

To all 'whomc't may-concern: f if l Be it known that LWVIYLLDR.` PORTER, a citizen of the United States, and a resident of Prince Bay, county of Richmond, State of New York, have invented certain new and useful Improvements in Dental-Engine Handpieces, of which the 'following Vis a specification, reference being had to the accompanying drawings. Y

My -'nvention relates particularly to that class of handpieces in which a tool-engaging chuck is actuatedby a relative 'axial movement of certain of the handpiece parts, and which is commonly known as pull-out and wedge type. l It is well known that this type of handpiece as heretofore constructed when eX- tended axially to clamp the tool by actuation ofthe clutch, 'a'portion of the slide or back spindle bearing is necessarily exposed, and it is difficult, iflnot impossible, for the operator toy prevent contact of the hand with the oily surface of such exposed portion.'

The principal objectof my invention is' to provide a handpiece of such simplified construction as to render possible the provision of means to prevent contact of the operators j hand with the interior partsthereof. i

' Other objects of my invention 'are to provide a 'handpiece with a front spindle'and a backspindle or driving'shaftgwhich may be operatively connected by interlocking members formed on the yadjacent ends of the back 'spindle and wedge slide, to afford a substantially universal joint, andy arranged to be engaged-and 'disengaged by ak lateral relatively sliding movement Lof said part into and out of axial alineinent.

My linvention further comprehends novel means for, engaging the handle section or sheath with the union section or collet, and

for adjusting said sheath thereon and determiningits axial position.

Specifically stated, the form of my invention as hereinafter described, comprehends a handpiece comprising a front spindle 'connected through fthe `wedge slide with the back spindle or shaft by a-.T-he'ad and undercutsocket joint; a slide or bearing for said back 'f spindle or shaft, having its rear end 'enlarged' to provide an; annular head;y 'a

anion-Section 0r collet forming a shamev or pushing embracing saidslide or bearing; a

specification of Lettesratenf; Patentedlsept. 27, '1921.

sheathy in threaded engagement withsaid f collet, the axial position of the sheath being determined by a split nut also in threaded engagement with said collet and adjustable thereon; and a` tubular shield removably attached to said head, and supported thereby in telescopic relation with said sheath.

VMy invention also includes all of the various novel features of constructionk and arrangement as yhereinafter more definitely specified. Y A

In the accompanying drawings, Figure l is a central longitudinal sectional view of a handpiece constructed inaccordance with my invention; Fig. 2 isa similar-central longitudinal sectional view vof said handpiece having its relatively movable parts axially extended to clamp the chuck onthe tool; Fig. 3 is a fragmentary lperspectiveA View of the universal connection between the driving shaft-and wedge slide 'or coupling; Fig. 4

. is a fragmentary sectiona'lview taken axially of said handpiece on the line .4--4 in Fig. 1, and showing the subtantially universal connection between thedriving shaft and wedge slide or coupling; Fig; 5 vis a transverse sectionall view talrenthrough the oil chamber on the line "5 5" in Fig. 1'; and

Fig.v 6 Vis `a transverse sectional view 'taken on mounted to slide longitudinallyy on` said bearing or slide 5.. The sleeve :or colletf is in threadedfen- `ga ement with the rear' end of thesheath '4,

an therefore, ma A be "adjusted 4`axially therein and `retaine in such adjusted position by lthe sheath adjusting 'locknut 7 whichis also i-nthreaded engagement with saidV sleeveorfcollet'@ j y The driviiig shaft .bearing or slidew5` is 'clnvnently provlliedv w1th; vthe kyW-y .9

into which the collect key in the collet 6 may extend to prevent the relative rotation of said collet 6 and slide 5, but permitting their free relative movement in an axial or longitudinal direction.. l

The slide 5. has its rear end enlarged to provide an annular head 12 having the forwardly extended threaded bossv 13 which conveniently carries the tubular shield 15v extended forwardly and disposed in tele` scopic relation with the sheath 4 and serving as a protection to the'exposed oily exterior surface of the slide 5 when the sheath 4 is extended with respect to said slide 5 to clamp the tool as hereinafter described.

Said head 12 is also provided-with a rearwardly extended threaded boss 16 arranged to carry a slip joint ferrule or a cable sheath of well known construction, and said boss 16 is provided with a recess 2O arranged to receive the back spindle collar 21 which 'is secured to the back spindle or drivingshaft 3 by the set screw 22. The rear end '23 of the back-spindle or driving shaft 3 is reduced and provided with screw threads 24 arranged to receive the end of a flexible driving cable of well-known construction.

The forward end' of the bach. spindle or driving shaft 3 isv enlarged to 'forni the cylindrical head 25 and is-provided with the undercut transversely extending Vslot 26.

which is arranged" to receive the T-headed projection 27 of the wedge slide or. coupling 2`litted therein with suiiicient looseness to afford a substantially universal joint whereby the rotation of lthe baclr spindle or driving shaft 3 effects the rotation. of said wedge slide or coupling 2. i

Said wedge slide. 2 is provided at its forward 'end with the projecting key or spline 30 extending into a suitable slot or lreyway 31 in the wall of the forward spindle 1 which is mounted for rotation in the sheath 4. The forward end of said forward spindle 1 is supported in the conical bearing 337 and the back end is arranged-to rotate in the bearing provided by'thel cylindrical sheath bushing 34;mounted inthe recess 35 in the wall of the bore ofsaid sheath V4. An end thrust bearing washer 36vis disposed in the bore of the sheath `4 and alfords anend thrust bearing for the f forward spindle 1.

The forward spindle 1 is provided Awith the transversely disposed slot .37 intersecting the slot. 31 and serving as abearing for the trunnions 39 of the lever 40, which is dis'- posed for oscillation in thetslot 41 in the wedge slide or coupling2, andlwhich has, its

free end inclined to bear against the serrated wall 42 of said slot,`so that said .free end may engage any one of the serrations and serve to lock the parts of the handpiece in their relatively adjustedpositions when extendedyas Shown in Fig. 2.

The lever 40 is arranged to effect Ythe .plunger 49,v which carries the plunger tip 50 arranged to be engaged by the elbow 51 of the lever 4,0 so that when the relatively Slidable members of the handpiece areshifted to cause the lever40 to ride upon the serrated wall 42. the elbow 51 forces the plunger 49 forwardly against the chuck 46 and by cooperation ofthe conical ends ofsaid chuck withthe conical 'surfaces 47 and 48 itis vcontracted to embrace the tool 45 therein with'su'ch pressure as' to firmly hold said tool in its operative position.` i

The collet6`is provided withtheoil hole 52 which registers with a'suitable opening 53 in the slide 5 for the injection of oil into the annular chamber 55 between the driving'shaft3 and its bearing in the slide 5, formed bythe reduced region 56 of said drivingshaft 3. Said oil hole 52 is normallyV covered by the sheath 47 and is accessible' by the mere removal of said sheath.

rlhe head 12 of the slide 5 is conveniently provided withrthe aperture 57 into which a bodlin or other suitable `tool may be inserted for holding said head when it is desired to remove or separate the handpiece parts by relative rotation.

1t willbefreadilyseen: that the slightest wear of the .parts in their bearings maybe taken up by 'loosening lthev sheath-adjusting nut 7 and rotating the sheath 4on the collet 6 until the adjustment of the bearings is attained, which adjustment may be maintained by 'j amining they sheath-adjusting nut 7 into en'gag'ementrwith the endof the sheath 4. Said sheath nut 7 may preferably be split as lshown at 60'l and `by its spring pressure tightly -clampsthe collet 6. f

My invention is advantageousin that the parts of the handpiece may be takenapart and assembled bythe removalof a single set screw 22- andthe sheath 4 which permits the withdrawal of thebaclr'spindle or driving jshaft 3 from its bearing inthe slide 5, and 'when thus released from said bear1ng,".the

wedge'slide 2maybe separated from said back spindle or driving shaft 3 by simpl)T sliding them oppositely in aflateral direction to release the T-head 27 on said wedge slide 2from the undercut slot 26 in the head 25of thebafclr spindle or driving shaft3.-

Furthermore, by the construction herein contemplated', the space between the relatively slidable members isbridged by the shield 15V so as tobprotect the oily exterior .surface'of r'the' slide 5, and thereby prevent the. hands olf the operator from beingsoiled by fcontact therewith, s

I do not desireto limit my invention to the precise details of construction and arrangement as herein set forth, as it is obvious that various modifications may be made therein Without departing from the essential features of my invention as defined in the appended claims.

Having thus described my invention, 'I claim 1. A dental engine handpiece having a shield arranged to prevent contact of the operators hand With the interior parts thereof.

2. A dental engine handpiece having'a sheath and a shield in telescopic relation With the sheath, arranged to prevent contact of the operators hand with the interior parts thereof.

3. A dental engine handpiece having a sheath, and relatively movable members arranged to actuate a tool-holding clutch, and a shield carried by one of said members in telescopic relation with vsaid sheath.

4. A dental engine handpiece having a front spindle` and a back spindle or shaft, the adjacent ends of said spindles being kprovided With interlocking members embodying means tending -to maintain them substantially coaxial when rotated one by the other and arranged to be readily connected and disconnected. v

5. A dental engine handpiecey having a` to be readily connected and disconnected by a relative sliding movement laterally.

7. A dental engine handpiecey comprising a front spindle connected With the back spindle by a T-head and socket joint, a casing or bearing for said back spindle, having its rear end enlarged to provide an annular head, a collet or sleeve embracing said bearing, a sheath in threaded engagement with said collet, and a tubular shield carried by said head in telescopic relation with said sheath.

8. A dentalengine handpiece comprising a front spindle connected with the back spindle or shaft by aAT-head and socket joint, a casing or bearing for said shaft having an annular head, al collet or sleeve embracingk said bearing, a sheath in threaded engagement with said collet, a nut also in threaded engagement with said collet adjustable thereon to determine the axial position of said sheath, and a tubular shield removably attached to said head and sup* ported thereby in telescopic relation to said sheath.

9. Aidental engine handpiece comprising a driving shaft, a bearing for said driving shaft having an oil chamber surrounding said shaft and provided With an inlet, a collet embracing said bearing, and having an oil aperture in registry with said inlet, and a sheath inthreaded engagement with said collet arranged to close said aperture.

In Witness whereof, I have hereunto set my hand this 21 day of September, A. D.

Witnesses:

SAMUEL R. BARTON, i CLnrroN C. HALLOWELL. 

